Application of natural shoulder delivery combined with free position delivery in maternal delivery.

OBJECTIVE: This research was designed to probe into the influences of natural shoulder delivery combined with free position delivery on pregnant outcome and genital tract of puerperants. METHODS: Totally 128 puerperants who gave birth in our hospital from May 2018 to November 2019 were selected as the research objects. Among them, 66 in traditional position combined with traditional shoulder delivery were assigned to a conventional group (CG), and 62 in free position combined with natural shoulder delivery were assigned to a research group (RG). Their psychological mood, pain degree, pregnancy outcome, labor time, postpartum recovery and genital tract injury were compared. RESULTS: Compared with the CG, the scores of visual analogue scale (VAS) pain, postpartum self-rating depression scale (SDS) and self-rating anxiety scale (SAS) in the RG during delivery were lower (P<0.05); the first, second, third and total labor stages in the RG were shorter (P<0.05). What's more, in the RG, the incidences of lateral episiotomy, urinary retention, stress urinary incontinence, transit cesarean section, shoulder dystocia and neonatal asphyxia were lower, while the perineum integrity and natural delivery rates were higher (P<0.05); the postpartum height of uterus, lochia discharge and blood loss were lower, while milk yield was higher (P<0.05). CONCLUSION: Natural shoulder delivery combined with free position delivery can effectively improve the pregnancy outcome, benefit the postpartum recovery, shorten the labor process and reduce the degree of genital tract injury. Hence, it is worthy of clinical application.

A novel label-free solid-state electrochemiluminescence sensor based on the resonance energy transfer from Ru(bpy)32+ to GO for DNA hybridization detection.

Based on electrochemiluminescence resonance energy transfer (ERET) from Ru(bpy)32+ to graphene oxide (GO), a novel label-free solid-state ECL sensor for sensitive detection of DNA was proposed. First, Ru(bpy)32+/AuNPs was successfully prepared by using a simple and green method and characterized by transmission electron microscopy (TEM), Energy Dispersive X-ray (EDX), and UV-vis spectroscopy. Then, the Ru(bpy)32+/AuNPs colloid was assembled on the gold electrode surface for solid-state ECL film which also later could be used to immobilize thiol-derivatized, single-stranded DNA (HS-ssDNA) via Au-S interactions. The stepwise modification procedure was characterized by cyclic voltammetry(CV), electrochemical impedance spectroscopy (EIS), probe approach curves (PAC) and ECL, respectively. The resulting modified electrode was tested as ECL biosensor for DNA detection. Upon addition of GO, the strong noncovalent interaction between HS-ssDNA and GO led to ECL quenching because of ERET. When in the presence of target ssDNA (t-ssDNA), the distance between the HS-ssDNA and GO increased, which significantly hindered the ERET and, thus, resulted in the restoration of ECL. The ECL intensity of the biosensor increased linearly with t-ssDNA concentration in the range of 50-1000pM, and the detection limit is 20pM. To the best of our knowledge, this is the first application of solid-state ERET from Ru(bpy)32+ to GO and opens new opportunities for sensitive detection of biorecognition events.

Atmospheric chemistry of CF2ClO2: a theoretical study on mechanisms and kinetics of the CF2ClO2 + HO2 reaction.

The singlet and triplet potential energy surfaces of the HO2 with CF2ClO2 reaction have been probed at the BMC-CCSD/cc-pVTZ level according to the B3LYP/6-311++G(d,p) level obtained geometrical structure. On the singlet PES, the association/dissociation, direct H- abstraction, and SN2 displacement mechanisms have been taken into account. On the triplet PES, SN2 displacement and indirect H- abstraction reaction mechanisms have been investigated and the H- abstraction channel makes more contribution to the CF2ClO2 with HO2 reaction. The rate constants have been computed at 10-10 to 1010 atm and 200-3000 K by RRKM-TST theory. The results show that at T ≤ 600 K, the generation of IM1 (CF2ClO4H) by collisional deactivation is dominant pathway; at high temperatures, the production of P8 (CF2ClOOH + O2(3Σ)) becomes predominate. The predicted data for CF2ClO2 + HO2 agrees closely with available experimental value. Moreover, OH radicals act as inhibitors in the CF2ClOOH→CF2O + HOCl and CF2ClOOH→CFClO + HOF reactions. The dominant products for the reaction of CF2ClOOH + OH are CF2ClO2 + H2O.

Theoretical investigations on mechanisms and pathways of CH2ClO2/CHCl2O2 with ClO reactions in the atmosphere.

A global and systematic theoretical research on the singlet and triplet potential energy surfaces (PESs) of the CH2ClO2/CHCl2O2 with ClO reactions are done at the CCSD(T)//B3LYP level and accompanied with RRKM computations to forecast the mechanism and distribution of products. The simulation results revealed that, on the singlet PES, products P1 (CHClO + HO2 + Cl)/P1 (CCl2O + HO2 + Cl) from IM1 (CH2ClOOOCl)/IM1 (CHCl2OOOCl) are forecasted to the primary products of the CH2ClO2/CHCl2O2 + ClO reactions, which are initiated by the oxygen atom of ClO radical addition to the terminal-O atom of CH2ClO2/CHCl2O2 barrierlessly, while other product channels contribute less to the whole reactions owing to higher barriers. Two other isomers, including IM2 (CH2ClOOClO) and IM3 (CH2ClOClO2) for the CH2ClO2 + ClO reaction, and three other isomers, including IM2 (CHCl2OOClO), IM3 (CHCl2OClO2), and IM4 (CHCl2ClO3) for the CHCl2O2 + ClO reaction, could be produced as less significant products. RRKM calculations presented that the initial adducts IM1 (CH2ClOOOCl)/IM1 (CHCl2OOOCl) are the primary products at T < 400 K and T < 600 K, respectively, and products P1 (CHClO + HO2 + Cl)/P1 (CCl2O + HO2 + Cl) are dominant the reactions at T ≥ 400 K and T ≥ 600 K, respectively. The atmospheric lifetime of CH2ClO2 and CHCl2O2 in ClO is around 4.61 and 3.24 h, respectively.

A study on the electrochemical behavior of hydroquinone at a nanometer cobalt/l-glutamate-modified electrode.

A new electrochemical sensor for hydroquinone (HQ) was prepared. The electrochemical sensor was modified by electrodeposition and electrochemical polymerization to modify nanometer cobalt (nano-Co) and poly-l-glutamic acid (poly-l-glu) on the surface of a glassy carbon electrode (GCE). Then, the electrochemical behavior of hydroquinone on the electrochemical sensor was investigated by cyclic voltammetry (CV). The experimental conditions were optimized from the aspects of electrolyte type, concentration, acidity, enrichment time and scanning speed. The experimental results showed that under optimized conditions the oxidation peak current has a good linear relationship with the concentration of hydroquinone in the range of 3.85 × 10-6 to 1.30 × 10-3 mol L-1 (R 2 = 0.9998). Moreover, there was a low detection limit of 4.97 × 10-7 mol L-1. When the sensor was used for the analysis of hydroquinone in water samples, the recoveries with satisfactory results were in the range of 97.2-102.6%.

Computational study on the mechanisms and kinetics of the CH2 = CHCH2F with O(3P) reaction.

The potential energy surface for the reaction of O(3P) with CH2 = CHCH2F has been studied at the CCSD(T)//M06-2X level of theory. Three different reaction entrances were revealed, namely, terminal-C addition, central-C addition, and H(or F)-abstraction, leading to CH2OCHCH2F (IM1), CH2CHOCH2F (IM2) and HO + C3H4I (OF + C3H5), respectively. The corresponding activation barriers are 3.04 (TS1), 3.71 (TS2), 7.06 (h-TS1), 12.68 (h-TS2), 14.04 (h-TS3) and 63.58 kcal/mol (F-TS1) kcal/mol. Several conceivable decomposition and isomerization channels were also examined for IM1 and IM2. The total and individual rate constants were calculated by using Multichannel RRKM and TST theory over a wide range of temperatures (200-3000 K) and pressures(10-14-1014 Torr).The branching ratios indicate that IM1 is the major product at 200-800 K. The production of P1 (CH2FCHCHO + H)via H-elimination from IM1 becomes dominant at high temperatures.

Determination of malachite green in fish based on magnetic molecularly imprinted polymer extraction followed by electrochemiluminescence.

A novel procedure for selective extraction of malachite green (MG) from fish samples was set up by using magnetic molecularly imprinted polymers (MMIP) as the solid phase extraction material followed by electrochemiluminescence (ECL) determination. MMIP was prepared by using Fe3O4 magnetite as magnetic component, MG as template molecule, methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. MMIP was characterized by SEM, TEM, FT-IR, VSM and XRD. Leucomalachite green (LMG) was oxidized in situ to MG by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). And then MMIP was successfully used to selectively enrich MG from fish samples. Adsorbed MG was desorbed and determined by ECL. Under the optimal conditions, calibration curve was good linear in the range of 0.29-290 µg/kg and the limit of detection (LOD) was 7.3 ng/kg (S/N=3). The recoveries of MMIP extraction were 77.1-101.2%. In addition, MMIP could be regenerated. To the best of our knowledge, MMIP coupling with ECL quenching of Ru(bpy)3(2+)/TPA for the determination of MG has not yet been developed.

Determination of m-dinitrobenzene based on novel type of sensor using thiol-porphyrin mixed monolayer-tethered polyaniline with intercalating fullerenols.

A novel sensor based on thiol-porphyrin mixed monolayer-tethered polyaniline (PANI) with intercalating fullerenols was applied to sensitively detect m-dinitrobenzene (m-DNB) by differential pulse voltammetry (DPV). The thiolated polyaniline was examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrode modification of thiol-porphyrin mixed monolayer-tethered polyaniline with intercalating fullerenols exhibited a higher analytical sensitivity versus that of thiol-porphyrin mixed monolayer-tethered polyaniline, because the fullerenols in mixed monolayer could improve the preconcentration efficiencies of m-DNB. Under optimum conditions, the linear calibration curves ranged from 0.029 to 10,000 nmol L(-1) for m-DNB, with a limit of detection (S/N=3) of 9.72 pmol L(-1).

An electrochemical glutathione biosensor: ubiquinone as a transducer.

In this paper, coenzyme Q10 (Ubiquinone, CoQ10) was used for the first time as a transducer to construct electrochemical biosensor for effectively detecting γ-L-glutamyl-L-cysteinyl-glycine (glutathione, GSH). CoQ10 modified electrode was fabricated by attaching its gel mixed with multi-walled carbon nanotubes (MWNTs)/ionic liquid (IL). In the optimum conditions, based on the increasing of reduction peak current of CoQ10 caused by GSH through voltammetric technology, it was found that the peak current of CoQ10 was linear with the concentration of GSH in the range from 4.0×10(-9) to 2.0×10(-7)mol L(-1) at the pH 7.00, and the limit of detection was 3.2×10(-10)mol L(-1) (S/N=3). The results revealed that this method could be used to determine GSH in actual blood samples with the superiority of excellent selectivity, high stability and sensitivity. The strategy explored here might provide a new pathway to design novel multi-function transducers for detecting GSH, which has unique characteristic and potential application in the fields of sensor and medical diagnosis.

Quenching of the electrochemiluminescence of Ru(bpy)3²âº/TPA by malachite green and crystal violet.

Efficient and stable quenching of electrochemiluminescence of Ru(bpy)3(2+)/TPA by malachite green(MG) and crystal violet(CV) at the glass carbon (GC) electrode is reported. A novel quenching mechanism has been proposed. Resonance energy transfer from the excited-state luminophore Ru(bpy)3(2+*) to MG/CV and dynamic quenching are suggested as the mechanism for quenching ECL. The quenching mechanism is discussed in detail based on UV-visible absorption spectra, cyclic voltammograms, ECL curves and fluorescence methods. MG shows more efficient quenching than CV. Moreover, the quenched ECL intensity versus the concentration of MG and CV are linear over the concentration ranges of 8 × 10(-10)-8 × 10(-7)M and 3.46 × 10(-9)-5.5 × 10(-7)M, respectively. The corresponding limit of detection (LOD) was 1.0 × 10(-10)M for MG and 1.1 × 10(-10)M for CV (S/N=3).

(Z)-4-Bromo-N-{(Z)-3-[(4-bromo-2,6-diisopropyl-phen-yl)imino]-butan-2-yl-idene}-2,6-diisopropyl-aniline.

The title compound, C(28)H(38)Br(2)N(2), is centrosymmetric with the mid-point of the central C-C bond of the butyl group located on an inversion center. The terminal benzene ring is approximately perpendicular to the central 1,4-diaza-butadiene mean plane [dihedral angle = 78.23 (3)°]. No hydrogen bonding or aromatic stacking is observed in the crystal structure.

Self-quenching in the electrochemiluminescence of tris(2,2'-bipyridyl) ruthenium(ii) using metabolites of catecholamines as co-reactants.

Electrochemiluminescence (ECL) of Ru(bpy)(3)(2+) using metabolites of catecholamines: homovanillic acid (HVA) and vanillylmandelic acid (VMA) as co-reactants were investigated in aqueous solution for the first time. When HVA and VMA were co-existent in the buffer solution containing Ru(bpy)(3)(2+), ECL peaks were observed at a potential corresponding to the oxidation of Ru(bpy)(3)(2+), and the ECL intensity was increased noticeably when the concentrations of HVA and VMA were at lower levels. The linear calibration range was from 8.0 × 10(-5) to 1.0 × 10(-9) M for HVA and VMA. The detection limit (S/N = 3) of HVA and VMA was 4.0 × 10(-10) M. The formation of the excited state Ru(bpy)(3)(2+*) was confirmed to result from the reaction between Ru(bpy)(3)(3+) and the intermediates of HVA or VMA radicals. Moreover, it was found that the ECL intensity was quenched significantly when the concentrations of HVA and VMA were relatively higher. The mechanism of self-quenching processes involved in the Ru(bpy)(3)(2+)-HVA and -VMA ECL systems are proposed in this study.

[Determination of diosgenin and ruscogenin in Radix Ophiopogonis by nonaqueous capillary electrophoresis].

Nonaqueous capillary electrophoresis is used for the determination of the contents of diosgenin and ruscogenin in Radix Ophiopogonis. The operating buffer was composed of 20 mmol x L(-1) Na2B4O7-HCl (pH 7.61) in 70% methanol. The applied voltage was 25 kV and detection potential was at +0.70 V. With these conditions, the components were successfully separated. The content of diosgenin in Radix Ophiopogonis was 0.018 mg x g(-1) and ruscogenin was 0.008 mg x g(-1). The average recoveries of diosgenin and ruscogenin were 102% and 99.2%, respectively. A new method of the quality control of diosgenin and ruscogenin in Radix Ophiopogonis is provided.